Most present day braking systems are dissipative in nature in that they convert kinetic energy of motion into waste heat and concurrent wear of the braking parts. This applies to automobiles, trains, motorcycles, and other vehicles, as well as to stationary industrial systems. Thus, whenever a present day moving vehicle is slowed or stopped, its kinetic energy is dissipated as heat by the braking system. The lost energy must subsequently be replaced by an increased consumption of fuel when the vehicle is subsequently accelerated back to its cruising speed. This results in a tremendous waste in energy, especially in urban areas where traffic patterns necessitate repeated accelerations and decelerations of the vehicle.
The system of the present invention, however, provides a mechanism in which the kinetic energy from the moving vehicle during a braking action is stored until it is required for the acceleration of the vehicle up to its cruising speed, or for maintaining the vehicle at cruising speed. Apart from obviating waste energy, the system of the invention is not subject to wear during the braking intervals, and it does not contaminate the atmosphere with brake lining particles.
Another problem having environmental impact is the inability of most present day transmission systems to couple power sources, such as internal combustion engines, to the drive shaft of the vehicle with optimal efficiency for varying speeds and power requirements of the vehicle. Fixed ratio transmissions of the prior art, for example, require engines to run over a range of speeds a major portion of the time, and thereby to operate at off-peak efficiency. The prior art continually variable transmission, which allows the power source to run at a constant speed at which engine efficiency is a maximum, has not proven to be economically feasible because of the cost, complexity and wear inherent in that type of transmission.
The inertial-turbine system of the present invention provides a simple, feasible, reliable and efficient energy storage system into and from which power can be added or removed at will. Moreover, the system of the invention is capable of receiving or discharging energy at peak efficiency over a wide range of speeds, and without expensive and complicated transmission and clutching systems, variable speed traction drives, electromechanical speed conversion units, or the like.
The acceleration requirements of present day transportation systems increase materially the required peak horsepower of the energy sources. The cruising power requirements of most vehicles are usually an order of magnitude less than the acceleration power requirements. Thus, engine size and cost are relatively high due to the acceleration requirements. The prior art secondary power boost systems which are intended to decrease the peak power engine requirements have not proven to be economically feasible due to their inherent complexity and high cost.
The system of the present invention is constructed to handle peak power requirements during acceleration without any need to increase engine sizes, as is the case in the prior art transmission systems. The inertial-turbine system to be described herein stores energy in a fluid flywheel. The fluid used to store the energy inside the rotating flywheel shell is also used to transfer energy to and from the flywheel shell during braking and acceleration. The system of the invention is constructed to effect optimal energy transfer between the flywheel and the drive shaft of the vehicle over a wide range of relative speeds. The system permits external operator-controlled flow of the working fluid into and out of the flywheel shell to dictate the braking and acceleration levels of the system within prescribed limits, while obtaining optimal energy transfer between the flywheel and the drive shaft at all speeds.
The inertial-turbine system of the invention, moreover, permits complete decoupling of the drive shaft from the flywheel without any requirement for mechanical clutches. In addition, the system can provide a required braking torque at any speed level, upon demand. When non-optimal relative speeds occur between the flywheel and the drive shaft because of external demands, the system will quickly and automatically move to optimize the energy transfer between the flywheel and the drive shaft, or vice versa.
Any appropriate working fluid can be used in the system of the invention, although mercury is presently preferred because of its high density.